This invention is an improvement in the field of rain gutters in general and specifically to those which screen out the majority of the debris before it can enter, and eventually foul, the gutter trough or pipe.
There are three principal types of debris, and a successful design must prevent each type from entering the gutter trough. The first type is large debris, typically leaves. Leaves are perhaps the easiest to remove by screening, but also the most likely to clog the screen, rendering it ineffective. The second type of debris is nuts, such as acorns. These cause the worst problem in a rain gutter because they never degrade, remaining in the rain gutter for years. The third type of debris is the small debris, typically pine needles or the blossoms of deciduous trees in the spring. These are the most difficult to separate because they go through a fine mesh.
The prior art includes innumerable designs intended to accomplish this function, without degrading from the primary function of the rain gutter, conveying all of the rain into the drainage pipes and away from the foundation of the building. A third function, also addressed in the prior art, is to reduce the susceptibility of the rain gutter to damage from ice as the ice slides off the roof of the building.
One widely used system is covering the conventional gutter trough with a screen. This system has several practical limitations. The mesh of the screen can trap leaves on top of the screen and prevent much of the rain from entering the gutter trough, particularly during a heavy rain. The screens are attached after the gutter trough is installed and the attachments often become loosened after time as ice slides off the roof, dislodging the screen.
U.S. Pat. No. 5,016,404, to Briggs, discloses a gutter trough above which is a curved metal or plastic sheet 80. The apex of the sheet extends beyond the lip of the gutter trough. The rain enters the gutter trough through a small aperture on the reverse slope of the curved sheet. There is no strainer to prevent the smaller debris from entering the pipe 16, although the orientation of the parts will allow larger debris, such as leaves to simply fall to the earth.
U.S. Pat. No. 4,876,827, to Williams, has an elongated trough portion 14 extending from the trough up to the roof line and under the shingles. A "water shed" portion 19 has a vertical lower portion and a curved upper portion. Water from the roof slides over the curved portion and then down the vertical portion, which has apertures whose purpose is to allow the water but not debris to enter the gutter trough.